Self-winding mechanism for timepieces



April 23, 1963 R. H. ERARD SELF-WINDING MECHANISM FOR TIMEPIECES Filed Sept. 12, 1960 2 Sheets-Sheet 2 Unite States This invention relates to self-winding mechanisms for time-pieces and in particular to the means used to transmit motion from the power means ensuring self-winding to the barrel arbor.

Many types of motion transmitting means for selfwinding mechanisms have already been proposed to convert the reciprocating or oscillating movements of a member belonging to or actuated by power means such as for instance an oscillating weight, a member of a thermometer, a barometer and the like into unidirectional rotary motions of a gear operatively connected to the barrel arbor of the timepiece to wind up the main spring thereof.

It is now an object of this invention to provide new and particularly efiicient means to transmit a reciprocating or oscillating motion of the power means or a part thereof into unidirectional rotary motions of a gear.

Further objects of the invention will become apparent in the course of following description.

One embodiment of the self-winding mechanism according to the invention is represented diagrammatically and by way of example in the drawings annexed to this specification and showing only the parts of said embodiment which are necessary for the comprehension of the invention.

In the drawings:

FIG. 1 is a part sectional view of a watch movement embodying the invention, and

FIG. 2. is a partial plan View of said watch movement, with some parts broken away.

The self-winding mechanism represented in the drawings is actuated by power means comprising a winding weight 1 mounted for rotary motions about a trunnion fixed in the center of the movement on to a frame part thereof, as for instance the upper wheel bridge 2. The winding weight 1 can have any one of the conventional shapes and configurations. It can be mounted either for rotary motions all round the watch movement or only for limited motions. In any case this weight 1 has a heavy peripheral sector 3 connected to a hub portion 4 by means of arms or of a thin plate 5.

The rotary motions of weight 1 are transmitted to the barrel arbor 6 by means of a mechanism comprising a motion transmitting member 7 mounted for tilting motions within the watch movement frame work. Motion transmitting member 7 consists of a shaft 8, a driving gear 9 and a toothed wheel 10, said gear and said wheel being rigidly secured or made integral with shaft 8. This shaft 8 is mounted for rotary and for tilting motions within the watch movement frame by means of a lower and an upper pivot 11 and 12, respectively. Pivot 11 comprises a spherical surface portion 13 which serves to journal pivot 11 within a cylindrical bore of a bearing provided in the watch movement base-plate 14.

Instead of having a spherical pivot located in a cylindrical bore of the bearing, shaft 8 could also be provided with a cylindrical lower pivot journalled within a bore having a side surface with a substantially hyperbolic shape or even with a conical shape.

Pivot 12 extends through an elongated slot 15 provided in an upper watch movement bridge 16 which can be the barrel bridge or :also the upper wheel bridge. Slot 15 extends in a radial direction with respect to the watch movement so that shaft 8 can tilt in a radial plane of said atet ice

movement. The upper pivot 12 is cylindrical and it extends in a bore with hyperbolic shape of a roller 17 so as to be journalled therein. As for the lower pivot, this upper pivot could also be provided with a spherical surface portion journalled in a cylindrical bore of roller 17. As shown in FIG. 1, roller 17 lies on the upper surface of bridge 16.

The motion transmitting member 7 is operatively connected to the winding weight 1 by means of a sinuous groove 18 provided in a thicker portion 19 of the winding weight 1. With a weight 1 mounted for free rotations all round the movement, the portion 19 and the groove 13 also extend all round the weight axis of rotation. As shown in the drawings the roller 17 is located within groove 18, the width of which almost corresponds to the diameter of roller 17.

When weight 1 is moving around the watch movement, its sinuous groove 18 reciprocates roller 17 held by pivot 12 in a radial direction determined by slot 15 through which pivot 12 is extending. A rotary motion of weight 1 is thus converted in a reciprocating tilting motion of shaft 8 about a fulcrum defined by the center of the spherical surface portion 13 of pivot 11, said tilting motion occurring in a radial plane of the watch movement.

To reduce the friction between weight 1 and roller 17, the latter is provided with a spherical outer surface portion engaging the vertical side faces of groove 18.

The tilting motion of shaft 8 is converted into unidirectional rotary motions of motion transmitting member 7 about the axis of shaft 8 by means of a couple of spring pressed detents or pawls 20 and 21 engaging the wheel 10 secured on to shaft 8. The pawls 20, 21 are pivotally mounted on pins 22 rigidly secured onto an intermediate bridge 23 of the watch movement framework fixed itself to the baseplate 14. The pawls 20, 21 are given such an orientation with respect to the wheel 10 that the latter, which is provided with a ratchet toothing as shown in the drawings, is only permitted of rotating in one direction about shaft 8. The pawls 20, 21 are always kept in engagement with wheel 10 by means of a V-shaped spring 24 having bent up ends secured to pawls 20, 21 within bores provided therein.

Now, if the shaft 8 is tilting outward with respect to the watch movement, pawl 20 serves :as fulcrum while pawl 21 jumps over the teeth of wheel 10 which is rotating about said fulcrum and consequently also about its axis. On the contrary, when shaft 8 is tilting inward it is pawl 21 which serves as fulcrum while pawl 20 is jumping over the teeth of wheel 10. In both instances the Wheel 10 is rotating in the direction of arrow a about its axis.

It will be noted from this description that the pawls 20, 21 are advantageously located in such a position with respect to the elongated slot 15 of bridge 16 that their ends engaging wheel 10 lie on a diameter of this wheel which is perpendicular to the direction of slot 15. Another location of pawls 20, 21 would of course also be operative but the described arrangement of these pawls with respect to slot 15 ensures an operation with the highest possible efficiency.

In the mean position represented in full lines in the drawings, the shaft 8 is perpendicular to the watch movement, while in its end positions this shaft 8 is inclined as represented in broken lines in FIG. 1. The oscillatory tilting motion of shaft 8, controlled by the sinuous groove 18 of the winding weight 1, should have a stroke kept below a limit as small as possible. The stroke of shaft 8 depends on the amplitude of the sinuous groove 18 so that the latter should not differ too much from a mean circle. The stroke of shaft 8 must obviously be kept as small as possible not only in order to avoid wheel 10 going out of engagement with pawls 2% '21, but also in order to keep the gear 9 provided on shaft 8 in normal driving conditions.

The rotary motions of gear 9 are transmitted to the barrel arbor 6 by means of a usual gear train. Therefore gear 9 is in meshing relation with a wheel 25 forming part of a step down gear operatively connected to arbor 6 by means of a pinion 26 fixed with respect to wheel 25 and of a wheel 27 secured to the barrel arbor 6 to wind up the main spring of the watch movement upon a rotation of driving gear 9.

The meshing conditions of gear 9 and wheel 25 are the better, the nearer gear 9 is set to the tilting fulcrum of shaft 3. FIG. 2 shows that the axis of wheel 25 is located in a plan perpendicular to slot 15 and passing through the mid-point of this slot.

It will be observed that if the barrel arbor is actuated for instance by means of a manual winding mechanism, the Wheel It) can rotate therewith freely, without tilting shaft 8. It will further be observed that the mechanism described for transmitting the motions of the winding Weight to the barrel arbor is entirely located within the watch movement frame.

Instead of power means consisting of a self-winding weight, other power means could also be provided to produce the oscillatory tilting motion of shaft 8. A member expanding or contracting upon temperature or pressure differences could thus for instance also be used as power means.

While one embodiment of my invention has been disclosed with reference to the accompanying drawings, it should be understood that various changes in the shape, sizes and arrangement of parts could be resorted to without departing from the spirit of the invention or sacrificing the advantages thereof.

I claim:

1. In a self-Winding mechanism for timepieces, in combination, a watch movement frame including two extreme parts and an intermediate part, which parts are superimposed and fixed to one another, a motion transmitting member disposed in said watch movement frame both for rotary and for oscillatory tilting motions and comprising a shaft having a portion disposed in one of said extreme parts for holding this portion pivotal with respect to said watch movement frame, another portion of said shaft being disposed in the other extreme part for transverse movement therein with respect to said watch movement frame, a driving gear and toothed wheel fixed to said shaft, and pawl means mounted on said intermediate part and acting on said toothed wheel to permit rotary motion of said motion transmitting gear in one direction for converting the oscillatory tilting motion of said motion transmitting member into unidirectional rotary motions of said driving pinion.

2. The combination of claim 1 in which the other extreme part includes an elongated slot guiding said other portion of said shaft so that said shaft tilts in a plane, the one extreme part of said portion of said shaft is held pivotal, defines a fulcrum, and said driving gear is disposed substantially close to said fulcrum.

3. The combination of claim 1, further comprising a lower bearing disposed in said one extreme part and an upper elongated slot disposed in the other extreme part, said shaft having one end journalled in said bearing and its other end guided for oscillatory sliding motion by said slot.

4. The combination of claim 1 further comprising an oscillating weight mounted for free rotary motion about a fixed axis on and above said Watch movement frame, said oscillating weight operatively connected to said shaft to produce tilting motion thereto.

5. The combination of claim 4, said oscillating weight having a sinuous slot disposed therein, and the other portion of said shaft carrying a roller located within said sinuous slot and guided thereby.

6. In a self-winding mechanism for timepieces, in combination, a frame including two extreme parts, a rotary driven. member journalled Within said frame, a motion transmitting member mounted in said frame for rotary and for oscillatory tilting motions with respect thereto and comprising a shaft, a first shaft portion disposed in one extreme part to hold this portion pivotal, a second shaft portion disposed in the other extreme part for transverse movement and guided thereby, a driving gear fixed on to said shaft and meshing with said driven member and a toothed wheel also secured to said shaft, pawl means rockably arranged on said frame and cooperating with said wheel to permit rotary motions of said mem her only in one direction thus converting the oscillatory tilting movements of said member into unidirectional rotary motions of said driving gear and of said driven member, and an oscillating power member mounted on an axis on said frame and guiding means disposed in said oscillating power member for cooperating with a third portion of said shaft projecting above the other extreme part to produce said oscillatory tilting motion of said motion transmitting member when the oscillating power member is moving about the axis thereof.

References Cited in the file of this patent UNITED STATES PATENTS 2,339,404 Hibbard Jan. 18, 1944 2,451,840 Lewandowski Oct. 19, 1948 2,696,073 Langel Dec. 7, 1954 2,744,413 Schneider May 8, 1956 FOREIGN PATENTS 1,119,081 France Mar. 26, 1956 

6. IN A SELF-WINDING MECHANISM FOR TIMEPIECES, IN COMBINATION, A FRAME INCLUDING TWO EXTREME PARTS, A ROTARY DRIVEN MEMBER JOURNALLED WITHIN SAID FRAME, A MOTION TRANSMITTING MEMBER MOUNTED IN SAID FRAME FOR ROTARY AND FOR OSCILLATORY TILTING MOTIONS WITH RESPECT THERETO AND COMPRISING A SHAFT, A FIRST SHAFT PORTION DISPOSED IN ONE EXTREME PART TO HOLD THIS PORTION PIVOTAL, A SECOND SHAFT PORTION DISPOSED IN THE OTHER EXTREME PART FOR TRANSVERSE MOVEMENT AND GUIDED THEREBY, A DRIVING GEAR FIXED ON TO SAID SHAFT AND MESHING WITH SAID DRIVEN MEMBER AND A TOOTHED WHEEL ALSO SECURED TO SAID SHAFT, PAWL MEANS ROCKABLY ARRANGED ON SAID FRAME AND COOPERATING WITH SAID WHEEL TO PERMIT ROTARY MOTIONS OF SAID MEMBER ONLY IN ONE DIRECTION THUS CONVERTING THE OSCILLATORY TILTING MOVEMENTS OF SAID MEMBER INTO UNIDIRECTIONAL ROTARY MOTIONS OF SAID DRIVING GEAR AND OF SAID DRIVEN MEMBER, AND AN OSCILLATING POWER MEMBER MOUNTED ON AN AXIS ON SAID FRAME AND GUIDING MEANS DISPOSED IN SAID OSCILLATING POWER MEMBER FOR COOPERATING WITH A THIRD PORTION OF SAID SHAFT PROJECTING ABOVE THE OTHER EXTREME PART TO PRODUCE SAID OSCILLATORY TILTING MOTION OF SAID MOTION TRANSMITTING MEMBER WHEN THE OSCILLATING POWER MEMBER IS MOVING ABOUT THE AXIS THEREOF. 